Really, you would have to put this guy at the top along with some of the other crime bosses.
Triads, Yakuza, Sicilian, Chicago and New York Mafia Heads.
Semion Mogilevich
Semion Mogilevich has been described by the FBI as the most dangerous mobster in the world. He is a Ukrainian-born organized crime boss who is believed to be the leader of the Russian Mafia. All decisions related to the expansion and organization of the syndicate is run by Semion Mogilevich. He is an extremely intelligent and ruthless leader who holds a degree in economics.
Mogilevich earned the nicknames ?Don Semyon? and ?The Brainy Don? because of his smarts. According to Wikileaks, Mogilevich has been connected with some huge companies, including RosUkrEnergo, Raiffeisen Bank, and Gazprom, which is a Russian state energy group. Semion Mogilevich rose to the position of godfather after he gained control of the Solntsevskaya Bratva. The Solntsevskaya Bratva is a powerful crime organization from Moscow named after the Solntsevo neighborhood in the city.
The syndicate is considered to be one of the most dangerous criminal groups in the world. They are known for a strict code of violence, drug smuggling, racketeering, illegal gambling, kidnapping, and contract killings. The Russian Mob is also one of the most profitable in the world and Semion Mogilevich is said to be a secret billionaire.